Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product, lowering pressure, then removing the ice by sublimation. This is in contrast to dehydration by most conventional methods that evaporate water using heat. 

Freeze drying food uses a process called lyophilization to lower the temperature of the product to below freezing, and then a high-pressure vacuum is applied to extract the water in the form of vapour. The vapour collects on a condenser, turns back to ice and is removed.

This means that the product’s water content transitions from a solid to a gaseous state — or from ice to vapor — without going through the liquid state.

The freeze-drying process can be divided into three steps:

1. Freezing: The product is often frozen under atmospheric pressure.
2. Primary drying: Also known as proper freeze-drying, this is the sublimation step in which frozen free water is removed.
3. Secondary drying: Also known as desorption drying, it’s the drying of products to their desired humidity by removing the remaining bound water.

TASTE

• Food Maintains
• Flavor and Freshness

NUTRITION

• Food Retains Nearly All of Its Nutrition

SHELF LIFE

• Food Lasts Up to 25 Years

Freeze-drying is considered a high quality dehydration method for a couple of reasons, including:

• it operates at low temperatures, which contributes to preserving a product’s nutritional value, taste, appearance, and heat-sensitive compounds
• freezing inhibits chemical and microbiological processes, which significantly delays the product’s deterioration (thereby extending its shelf life)

Freeze-drying retains nutritional value better than other drying methods, further supporting consumers’ desire for nutrition from whole foods. The process also preserves the actual color and shape of the original raw material, reassuring consumers they are actually getting real fruits and vegetables in their diets.

Freeze-drying is a way of dehydrating frozen food via a process that transforms ice into vapor, also known as sublimation. It is a healthy food preservation method, as it retains most of the beneficial plant compounds and nutrients in foods, as well as their color, taste, and appearance.